First part of information on gangs this month, plus HbA1c units compared, last bit on orthopaedic feet, a warning about phenytoin overdose and a couple of links to good relevant courses. Do leave comments below:

Sepsis and the “in-betweeners” this month. How to categorise the unwell children you are just not quite sure about. Also testing in malaria, the new NHSGo app and cardiac assessment prior to starting medications for ADHD. Do leave comments below:

There are over 300 new cases of imported paediatric malaria in the UK each year and cases of imported malaria here have been increasing over the last 20 years (1). Malaria in children is particularly difficult to diagnose because the initial presenting features are subtler than in adults. Children may appear quite well initially with a fever and no focus but; they are at risk of a rapid deterioration and are more likely to develop severe malaria.

The “gold standard” for ruling out the diagnosis of malaria if clinically suspected is three negative thin and thick blood films (2). This approach however, relies on serial phlebotomy and the availability of adequately trained staff. Furthermore, during out-of-hours periods the time and resources required are likely to result in delays in obtaining results especially if trained staff have to come in from home. There are now a range of Rapid Diagnostic Tests (RDTs) that are highly specific and sensitive for malaria. So are three films really required when we have RDTs?

There is only one study exploring the combination of blood films together with RDT’s in diagnosing imported malaria and it was in adults (3). Of the 388 cases, 367 (95%) were diagnosed by the initial blood film. Of the 21 that weren’t diagnosed on the blood film 19 had RDT’s performed. This diagnosed a further 10 leaving only 9 cases (2.3%) not picked up by a single blood film and RDT. Only one case of P.falciparum infection was missed and this was in a partially immune individual who had already received an unspecified treatment. The remaining 8 missed cases were P.vivax and P.ovale.

If we extrapolate from this study, then if a single blood film and RDT are negative a diagnosis of malaria is extremely unlikely. This is especially true in cases of suspected P.falciparum in a non-immune patient who has not received any treatment. The most obvious criticism here, is that it is difficult to extrapolate adult data and draw conclusions relating to children. However, the available data comparing parasite counts between children and adults suggests that on average children have a comparable or higher parasite count than adults (4). This would suggest that the results seen for adults would be comparable or even favourable in children.

Because of the paucity of data overall and lack of paediatric data it is not possible to make a blanket recommendation. The risk of malaria in each individual needs to be considered in conjunction with investigation results. For more information on diagnosing malaria in children read – How to interpret malaria tests (5).

Reintroduction of egg this month with thanks to the BSACI, benign acute childhood myositis, NICE on iv fluids plus a couple of links on when not to use this guidance and a comparison of algorithms for children with a non-blanching rash. Do leave comments below.

April 2016’s offering ripe for reading over the bank holiday weekend. Last text box from the 2014 BTS asthma guideline – this time on acute management, FGM and the importance of reporting colleagues who may be involved in the practice, Group A strep infection as a complication of chicken pox and some links to some good CPD sites for you and your patients.

We also welcome Dr Kat Smith this month, paediatric registrar and education fellow at King’s College Hospital, who has kindly volunteered to write monthly articles for the newsletter. It’s nice to have a fresh pair of eyes on paediatric topics and a fresh nose to the ground so to speak. Thanks, Kat, for your help.

With thanks to Dr Kat Smith, education fellow and paediatric registrar at King’s College Hospital who answered my call last month for more writers to help me put together the monthly Paediatric Pearls newsletters.

Group A Streptococcal Infection in Chickenpox

Chickenpox in children is common and usually follows a mild and self-limiting (if somewhat itchy) course. After an incubation period of 10-21 days the first signs of illness are viral prodrome, mild pyrexia, and the classic cropping vesicular rash; the pyrexia is typically mild (38-39oC) and lasts 3-4 days.

In otherwise healthy children the most common complication of chickenpox is secondary bacterial skin infection, typically caused by scratching lesions. Whilst most of these are mild impetigo or localised cellulitis, the increased incidence of group A streptococcal (GAS) colonisation in children (around 10% are asymptomatic carriers in the throat or on skin) makes invasive GAS infection a real concern.

Secondary bacterial skin infection

This is characterised by erythema +/- tenderness around lesions. Children may be well in themselves if the infection is superficial; if they become more unwell this raises the suspicion of a more serious or invasive bacterial infection.

Serious bacterial superinfection / Invasive GAS infection

Around a third of children admitted to hospital with chickenpox have secondary skin infection, some of whom develop invasive infections such as pneumonia, osteomyelitis and septicaemia. GAS in particular can be associated with more fulminant infectious processes such as necrotising fasciitis and toxic shock syndrome (TSS); both are associated with high mortality and morbidity in children.

Features that should prompt consideration of a serious bacterial superinfection are:

A lethargic or unwell-looking child; remember, children with chickenpox are typically uncomfortable but well.

Spiking, high-grade pyrexia

Pyrexia for longer than 4 days, particularly after initial improvement

Diarrhoea or vomiting

Soft tissue pain which seems disproportionate to other examination findings (an early sign of necrotising fasciitis)

How to prevent bacterial superinfection

Because scratching lesions is the most likely way to allow bacteria to breach the body’s normal defences, the primary aim of prevention is to limit scratching:

Keep skin moisturised. Many parents still use calamine lotion but it is worth noting that it becomes ineffective once dry, and traditional emollients (e.g. 50:50) may be more effective.

There is evidence that sedating antihistamines offer some benefit; chlorphenamine is licensed for this use.

Dress children in smooth, loose, cotton clothing.

Keep fingernails trimmed short.

There are rare reports of NSAIDs potentially worsening skin infections in chickenpox, so ibuprofen should be used with caution. In practice, it would be unusual for a child to need ibuprofen if receiving regular paracetamol; pain or pyrexia necessitating its use in addition to paracetamol should prompt consideration of serious bacterial superinfection.

There is no evidence to support the use of acyclovir in young, immunocompetent children with self-limiting, uncomplicated chickenpox; it does not decrease the incidence of complications.

What to do if you suspect bacterial superinfection

Otherwise well children with evidence of few, small areas of bacterial superinfection can be managed in the community with oral antibiotics and safety-netting advice.

Children with evidence of collection, extensive areas of bacterial superinfection, who are unwell, or have other features consistent with possible serious bacterial superinfection, need urgent referral to secondary care.

In secondary care, unwell children with evidence of shock / sepsis need urgent resuscitation and intravenous antibiotic administration; if possible this should include clindamycin, due to its vital role in inhibiting toxin production by GAS.

Invasive GAS infection has high mortality, and if suspected there should be a low threshold to involve senior staff, regional PICU services, and in the case of necrotising fasciitis, surgical teams (for early debridement); early use of inotropes and IVIG may also be required.

Re. “There is evidence that sedating antihistamines offer some benefit”

Tebruegge M, Kuruvilla M, Margarson I. Does the use of calamine or antihistamine provide symptomatic relief from pruritus in children with varicella zoster infection? Archives of Disease in Childhood. 2006:91(12);1035-1036.

Warts this month, steroids in Bell’s palsy, a recap of the year for the new trainees and some more edicts from NICE on what not to do. A couple of links to good CPD opportunities too. Do leave comments below.

Last bit of headaches this month with guidance on management of various primary headaches, including medication overuse headache. Also more on domperidone, psoriasis, respiratory and heart rates to worry about and a link to a new colic summary I’ve put under the Primary Care Guidelines tab. Do leave comments below.